This proposal covers work in two major areas of hydroxy fatty acid metabolism and function: (A) Biosynthesis and metabolism of prostaglandins in the gorgonian Plexaura homomalla. Two variants of P. homomalla re known: one producing prostaglandins with the R configuration at the 15-hydroxyl group; one with the S configuration. Structures of the C204 unsaturated fatty acid have shown to be arachidonic acid in both variants. Biosynthesis and metabolism of the prostaglandins will be studied using radioactive tracer techniques. (B) Yeast hydroxy acid sophorosides. The yeast Candida bogoriensis produces large quantities of an extracellular glycolipid--an acetylated sophoroside of 13-hydroxydocosanoic acid. A closely related yeast, a Torulopsis species, produces an acetylated sophoroside of 17-hydroxyoleic acid. This study will focus on the purification of the glucosyl and acetyl-transferases involved in the synthesis of these glycolipids, and hydrolytic enzymes involved in their metabolism. The properties of the enzymes will be studied in an attempt to ascertain their physiological function in the organism.